By Martyn Herman

LONDON (Reuters) - Second seed Andy Murray survived a ferocious Jo-Wilfried Tsonga fight back to reach the Wimbledon semi-finals for the seventh time, winning the Wednesday's second Centre Court blockbuster 7-6(10) 6-1 3-6 4-6 6-1.

After Roger Federer's miraculous earlier escape act against Marin Cilic, when he recovered from two sets down to win, 12th seeded Frenchman Tsonga threatened something equally improbable as dusk settled at the All England Club.

When the maverick Frenchman blazed away, firing winners from here, there and everywhere, to take the third and fourth sets Murray was wobbling. The crowd could barely believe their eyes.

But just when the match appeared to be spiralling out of control for the agitated Scot, the 2013 champion rediscovered his early authority to dominate the decider and set up a semi-final with Czech 10th seed Tomas Berdych.

"It was a tough match. At the end of the fourth set it was really tough," Murray, who had not dropped a set to reach the quarter-finals, said in a courtside interview.

"To lose that set 6-4 was hard but I tried to use all my energy at the start of the fifth to get myself pumped up, and the crowd, and thankfully got the break and managed to hang on."

After the memorable Federer exploits there was a danger that Murray's match against Tsonga might prove a mere footnote.

Those fears vanished in a high-quality opening set in which Murray was dragged into an epic 22-point tie break despite forging ahead with an early break of serve.

Tsonga had lost both of his previous Wimbledon clashes with Murray and was on an eight-set losing streak against the Scot, but he showed no inferiority complex.

He ended a scintillating 20-stroke rally with a volley to move 6-4 ahead in the breaker, but Murray replied with an ace and devilish service return to set up a routine pass.

Tsonga spurned a third set point when skewing a backhand wide off a Murray second serve.

MAGIC MOMENT

He was made to pay as Murray produced a moment of magic to run down a drop shot and punch a backhand pass which the diving Tsonga netted at 10-10 -- the Scot roaring to the crowd and pumping his fist in defiance.

The second seed then claimed the opening set with a volley into an open court on his fourth set point.

Rock solid Murray was buoyant and the spirit ebbed away from Tsonga in a one-sided second set.

But the 31-year-old Frenchman roared back with some audacious attacking tennis and Briton Murray, for the first time in a tournament that had been stress-free before, looked flummoxed.

Murray, hot favourite after champion Novak Djokovic's third-round demise, lost concentration in the third set and Tsonga capitalised to extend the contest.

Murray led 4-2 in the fourth before Tsonga, winners flowing from his racket, reeled off four games in a row to send the match into a decider.

Tsonga had a break point at the start of the fifth as Murray shovelled a forehand into the net, but he slipped mid-rally and Murray snuffed out the danger.

The Briton broke in the next game and never looked back as he racked up his 100th Tour level match on grass -- second only amongst active players to seven-times champion Federer who could await in Sunday's final.

(Reporting by Martyn Herman; editing by Ken Ferris)